#include <bits/stdc++.h>
using namespace std;
int a[200005];
struct state{
int u, v;
long long nw, ow;
state(int x, int y, long long z, long long t) : u(x), v(y), nw(z), ow(t) {}
friend bool operator<(const state& x, const state& y){
if(x.nw - x.ow != y.nw - y.ow) return x.nw - x.ow < y.nw - y.ow;
return make_pair(x.u, x.v) < make_pair(y.u, y.v);
}
};
set<pair<int,int> > ranges; // picked ranges
set<pair<int,int> > options; // potential options (sorted by pair)
set<state> states; // potential options
set<pair<int,int> >::iterator isCovered(int x){
// checks whether x is covered?
auto it = ranges.upper_bound(make_pair(x, 1000000));
if(it == ranges.begin()) return ranges.end();
it--;
return it->second >= x ? it : ranges.end();
}
set<pair<int,int> >::iterator isOptionsCovered(int x){
// checks whether x is covered?
auto it = options.upper_bound(make_pair(x, 1000000));
if(it == options.begin()) return options.end();
it--;
return it->second >= x ? it : options.end();
}
long long qs[200005];
long long qsx[200005];
inline long long getSum(int idx){
return idx > 0 ? qsx[idx] : 0ll;
}
int main(){
int n;
scanf("%d",&n);
for(int i = 1; i <= n; i++){
scanf("%d",a+i);
states.emplace(i,i,a[i],0);
options.emplace(i,i);
qsx[i] = (i-2 > 0 ? qsx[i-2] : 0ll) + a[i];
qs[i] = qs[i-1] + a[i];
}
long long ans = 0ll;
for(int turn = 1; turn <= (n+1)/2; turn++){
auto cur = *states.rbegin(); // maximum potential weight
ans += cur.nw - cur.ow;
states.erase(cur);
options.erase(make_pair(cur.u, cur.v));
if(ranges.count(make_pair(cur.u+1, cur.v-1)))
ranges.erase(make_pair(cur.u+1, cur.v-1));
// left-joinable and right-joinable?
auto lchk = cur.u > 1 ? isCovered(cur.u - 2) : ranges.end();
auto rchk = cur.v < n ? isCovered(cur.v + 2) : ranges.end();
int targetL = lchk == ranges.end() ? cur.u : lchk->first;
int targetR = rchk == ranges.end() ? cur.v : rchk->second;
if(lchk != ranges.end()){
ranges.erase(lchk);
}
auto p = isOptionsCovered(cur.u-1);
// find the props of the state
if(p != options.end()){
long long nw = getSum(p->second) - getSum(p->first - 2);
long long ow = qs[p->second] - qs[p->first-1] - nw;
state ex(p->first, p->second, nw, ow);
states.erase(ex);
options.erase(p);
}
if(rchk != ranges.end()){
ranges.erase(rchk);
}
p = isOptionsCovered(cur.v+1);
if(p != options.end()){
// find the props of the state
long long nw = getSum(p->second) - getSum(p->first - 2);
long long ow = qs[p->second] - qs[p->first-1] - nw;
state ex(p->first, p->second, nw, ow);
states.erase(ex);
options.erase(p);
}
ranges.emplace(targetL, targetR);
if(targetL-1 >= 1 && targetR+1 <= n){
options.emplace(targetL-1, targetR+1);
long long cow = getSum(targetR) - getSum(targetL-2);
states.emplace(targetL-1, targetR+1, qs[targetR+1] - qs[targetL-2] - cow, cow);
}
printf("%lld\n", ans);
}
//printf("RANGES\n");
for(auto r : ranges){
//printf("%d %d\n", r.first, r.second);
}
//printf("OPTIONS\n");
for(auto r : options){
//printf("%d %d\n", r.first, r.second);
}
//printf("STATES\n");
for(auto r : states){
//printf("%d %d\n", r.u, r.v);
}
//printf("===\n");
return 0;
}
Compilation message
candies.cpp: In function 'int main()':
candies.cpp:92:11: warning: variable 'r' set but not used [-Wunused-but-set-variable]
92 | for(auto r : ranges){
| ^
candies.cpp:96:11: warning: variable 'r' set but not used [-Wunused-but-set-variable]
96 | for(auto r : options){
| ^
candies.cpp:100:11: warning: variable 'r' set but not used [-Wunused-but-set-variable]
100 | for(auto r : states){
| ^
candies.cpp:37:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
37 | scanf("%d",&n);
| ~~~~~^~~~~~~~~
candies.cpp:39:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
39 | scanf("%d",a+i);
| ~~~~~^~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
620 KB |
Output is correct |
2 |
Correct |
3 ms |
620 KB |
Output is correct |
3 |
Correct |
3 ms |
620 KB |
Output is correct |
4 |
Correct |
3 ms |
620 KB |
Output is correct |
5 |
Correct |
3 ms |
620 KB |
Output is correct |
6 |
Correct |
3 ms |
620 KB |
Output is correct |
7 |
Correct |
3 ms |
620 KB |
Output is correct |
8 |
Correct |
3 ms |
620 KB |
Output is correct |
9 |
Correct |
3 ms |
620 KB |
Output is correct |
10 |
Correct |
3 ms |
620 KB |
Output is correct |
11 |
Correct |
3 ms |
620 KB |
Output is correct |
12 |
Correct |
4 ms |
620 KB |
Output is correct |
13 |
Correct |
3 ms |
620 KB |
Output is correct |
14 |
Correct |
3 ms |
620 KB |
Output is correct |
15 |
Correct |
3 ms |
620 KB |
Output is correct |
16 |
Correct |
4 ms |
620 KB |
Output is correct |
17 |
Correct |
3 ms |
620 KB |
Output is correct |
18 |
Correct |
3 ms |
620 KB |
Output is correct |
19 |
Correct |
3 ms |
620 KB |
Output is correct |
20 |
Correct |
3 ms |
620 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
620 KB |
Output is correct |
2 |
Correct |
3 ms |
620 KB |
Output is correct |
3 |
Correct |
3 ms |
620 KB |
Output is correct |
4 |
Correct |
3 ms |
620 KB |
Output is correct |
5 |
Correct |
3 ms |
620 KB |
Output is correct |
6 |
Correct |
3 ms |
620 KB |
Output is correct |
7 |
Correct |
3 ms |
620 KB |
Output is correct |
8 |
Correct |
3 ms |
620 KB |
Output is correct |
9 |
Correct |
3 ms |
620 KB |
Output is correct |
10 |
Correct |
3 ms |
620 KB |
Output is correct |
11 |
Correct |
3 ms |
620 KB |
Output is correct |
12 |
Correct |
4 ms |
620 KB |
Output is correct |
13 |
Correct |
3 ms |
620 KB |
Output is correct |
14 |
Correct |
3 ms |
620 KB |
Output is correct |
15 |
Correct |
3 ms |
620 KB |
Output is correct |
16 |
Correct |
4 ms |
620 KB |
Output is correct |
17 |
Correct |
3 ms |
620 KB |
Output is correct |
18 |
Correct |
3 ms |
620 KB |
Output is correct |
19 |
Correct |
3 ms |
620 KB |
Output is correct |
20 |
Correct |
3 ms |
620 KB |
Output is correct |
21 |
Correct |
873 ms |
27948 KB |
Output is correct |
22 |
Correct |
843 ms |
29548 KB |
Output is correct |
23 |
Correct |
857 ms |
29676 KB |
Output is correct |
24 |
Correct |
362 ms |
29420 KB |
Output is correct |
25 |
Correct |
364 ms |
29388 KB |
Output is correct |
26 |
Correct |
360 ms |
29548 KB |
Output is correct |
27 |
Correct |
375 ms |
29804 KB |
Output is correct |
28 |
Correct |
379 ms |
29676 KB |
Output is correct |
29 |
Correct |
376 ms |
29676 KB |
Output is correct |
30 |
Correct |
403 ms |
29892 KB |
Output is correct |
31 |
Correct |
391 ms |
29548 KB |
Output is correct |
32 |
Correct |
397 ms |
29548 KB |
Output is correct |
33 |
Correct |
564 ms |
29392 KB |
Output is correct |
34 |
Correct |
563 ms |
29548 KB |
Output is correct |
35 |
Correct |
564 ms |
29420 KB |
Output is correct |
36 |
Correct |
861 ms |
29548 KB |
Output is correct |
37 |
Correct |
861 ms |
29676 KB |
Output is correct |
38 |
Correct |
839 ms |
29696 KB |
Output is correct |
39 |
Correct |
361 ms |
29420 KB |
Output is correct |
40 |
Correct |
363 ms |
29420 KB |
Output is correct |
41 |
Correct |
357 ms |
29420 KB |
Output is correct |
42 |
Correct |
375 ms |
29676 KB |
Output is correct |
43 |
Correct |
374 ms |
29548 KB |
Output is correct |
44 |
Correct |
372 ms |
29804 KB |
Output is correct |
45 |
Correct |
398 ms |
29676 KB |
Output is correct |
46 |
Correct |
393 ms |
29676 KB |
Output is correct |
47 |
Correct |
400 ms |
29676 KB |
Output is correct |
48 |
Correct |
558 ms |
29420 KB |
Output is correct |
49 |
Correct |
567 ms |
29548 KB |
Output is correct |
50 |
Correct |
563 ms |
29420 KB |
Output is correct |